Utilization of Bitter orange seeds as a novel source for recovery of pectin: Compositional and rheological characterization

The seeds from bitter orange, a by-product from the juice making step, hold the potential to facilitate novel, easy yet high quality pectin extraction. To test this hypothesis, the pectin from orange seeds (OSP) were extracted by distilled water and its compositional parameters and rheological behavior then evaluated. Results showed that galacturonic acid was the major component of OSP (~ 425 mg/g) confirming the purity of extracted pectin, followed by glucose and some minor neutral sugars. Mw, Rn and, Rz for the OSP were 4511.8 (kDa), 61 (nm), and 61.1 (nm), respectively. Rheological measurements showed shear-thinning behavior for OSP that by increasing temperature from 5 to 45 oC, the viscosity of the gum decreased. Power law fitted as the best rheological model describing the flow behavior of OSP. Strain sweep dynamic rheological measurements confirmed an entangled network structure for OSP and the addition of NaCl to the gum dispersion, decreased the consistency coefficient from 35.6 to 23.18 Pa.sn, while the flow behavior index remained unchanged. These results demonstrate for the first time that the OSP can be used as a new source of pectin, with likely a wide range of applications in food industry.

Hydrodynamics of spike proteins dictate a transport-affinity competition for SARS-CoV-2 and other enveloped viruses

Many viruses, such as SARS-CoV-2 or Influenza, possess spike-decorated envelopes. Depending on the virus type, a large variability is present in spikes number, morphology and reactivity, which remains generally unexplained. Since viruses' transmissibility depend on features beyond their genetic sequence, new tools are required to discern the effects of spikes functionality, interaction, and morphology. Here, we postulate the relevance of hydrodynamic interactions in the viral infectivity of enveloped viruses and propose micro-rheological characterization as a platform for viruses differentiation. To understand how the spikes affect virion mobility and infectivity, we investigate the diffusivity of spike-decorate structures using mesoscopic-hydrodynamic simulations. Furthermore, we explored the interplay between affinity and passive viral transport. Our results revealed that the diffusional mechanism of SARS-CoV-2 is strongly influenced by the size and distribution of its spikes. We propose and validate a universal mechanism to explain the link between optimal virion structure and maximal infectivity for many virus families.

Development and Thermophysical Profile of Cetyl Alcohol-in-Water Nanoemulsions for Thermal Management

This study focuses on the preparation, thermophysical and rheological characterization of phase change material nanoemulsions as latent functionally thermal fluids. Aqueous dispersions with fine droplets of cetyl alcohol (with a melting temperature at ~321 K) were prepared by means of a solvent-assisted method, combining ultrasonication with non-ionic and anionic emulsifiers. Eicosyl alcohol (melting at ~337 K) and hydrophobic silica nanoparticles were tested as nucleating agents. Droplet size studies through time and after freeze–thaw cycles confirmed the good stability of formulated nanoemulsions. Phase change analyses proved the effectiveness of eicosyl alcohol to reduce subcooling to a few Kelvin. Although phase change material emulsions exhibited thermal conductivities much larger than bulk cetyl alcohol (at least 60% higher when droplets are solid), reductions in this property reached 15% when compared to water. Samples mainly showed desirable Newtonian behavior (or slight shear thinning viscosities) and modifications in density around melting transition were lower than 1.2%. In the case of phase change material nanoemulsions with 8 wt.% content of dispersed phase, enhancements in the energy storage capacity overcome 20% (considering an operational temperature interval of 10 K around solid–liquid phase change). Formulated dispersions also showed good thermal reliability throughout 200 solidification–melting cycles.

Utilization of Bitter orange seeds as a novel source for recovery of pectin: Compositional and rheological characterization

The seeds from bitter orange, a by-product from the juice making step, hold the potential to facilitate novel, easy yet high quality pectin extraction. To test this hypothesis, the pectin from orange seeds (OSP) were extracted by distilled water and its compositional parameters and rheological behavior then evaluated. Results showed that galacturonic acid was the major component of OSP (~ 425 mg/g) confirming the purity of extracted pectin, followed by glucose and some minor neutral sugars. Mw, Rn and, Rz for the OSP were 4511.8 (kDa), 61 (nm), and 61.1 (nm), respectively. Rheological measurements showed shear-thinning behavior for OSP that by increasing temperature from 5 to 45 oC, the viscosity of the gum decreased. Power law fitted as the best rheological model describing the flow behavior of OSP. Strain sweep dynamic rheological measurements confirmed an entangled network structure for OSP and the addition of NaCl to the gum dispersion, decreased the consistency coefficient from 35.6 to 23.18 Pa.sn, while the flow behavior index remained unchanged. These results demonstrate for the first time that the OSP can be used as a new source of pectin, with likely a wide range of applications in food industry.

Chemical, Mineralogical, and Rheological Characterization of Regional Clays for Potential Use in Cosmetics and Pharmaceutical Products

Four clay samples from different deposits in the state of Sergipe, Brazil, were fractionated by dispersion and centrifugation for comparative tests with a standard commercial clay used for cosmetic and pharmaceutical purposes. For this, they were characterized by X-ray diffraction, X-ray fluorescence spectroscopy, measurements of cation exchange capacity, oil absorption and viscosity, in addition to particle sizes and plasticity indexes. The objective was to determine the physical and chemical properties of raw clays and the consequent granulometric fractions to evaluate their potential use in products with high added value. After fractionation, the samples showed significant amounts of smectite and kaolinite, which combined with the size, particle distribution, chemical composition, and high adsorption capacity, especially in the PDL and PV samples, make them potentially interesting for applications in pharmaceutical and cosmetic products, they can also be used in spas and esthetic centers for therapeutic purposes based on their softness and cation exchange capacity.

Honey Adulterated with Glucose Syrup: Rheological Modeling

Honey's reputation for its various both nutritional and medicinal benefits and pleasant taste ensures a sustained high demand for the product all over the world. However, honey supply is quite limited and seldom meets the demand, and consequently the product commands a relatively high price and is exposed to adulteration and imitation. Honey was adulterated with glucose syrup weight of 10%, 50%, 70% and 90%, and each sample was analysed. Pure honey at ambient temperatures exhibits peculiar non-Newtonian rheological behaviour. Adulteration with glucose syrup (a Newtonian fluid) drags its viscosity towards Newtonian flow behaviour. Malcolm Cross and Ostwald-de Waele Power-Law models were used to fit the rheological data, and the former fitted better than the latter. The behaviour indices in both models increased with increasing adulteration of honey with glucose syrup. Chromatographic characterizations of honey which provides an acceptable measure of honey quality corroborated the conclusions derived from the rheological characterization of this study.